As the fifth season of “Mad Men” ends tonight, there's been a good deal of buzz on the Internet and from critics about Matthew Weiner's little show. No one seemed to like Don's murderous dream sequence this year, but the jury is divided on Lane's knotty departure this week. The chatter continues about whether Joan degraded or empowered herself by agreeing to bed a potential Sterling Cooper client. And then, of course, there's Don: Some argue that he's changing. I think Don, the man who invented himself, is not so much changing as emerging. It's the times that are a-changing in Season Five and Don is feeling threatened: He's unsure of whether he can change with them.

Me? I'm still mulling the orange sherbet.

The scene occurred in the April 22 “Faraway Places” episode at an upstate New York Howard Johnson's restaurant, when Don insisted Megan try the orange sherbet. She hated it. In my “Mad Men”-addled mind, that scene has felt increasingly like an important clue to the show's enigmatic fifth season and it's all because of the damn ice cream.

Back in the day, Howard Johnson's was the nation's largest restaurant chain, with the restaurants instantly identifiable by their orange roofs to any traveler hitting any city or hamlet for the first time. Inside, the waitresses wore uniforms of sea-foam teal, matching the color of the weathervane-topped cupolas reaching heavenward from those gleaming orange roofs.

The restaurant company was founded by a real Howard Johnson in 1925. Every Howard Johnson's was known for its 28 flavors of ice cream, especially the fabled orange sherbet, and for dishes like fried clams.

Howard Johnson's was America's family restaurant, and that was the reason the company thrived for so long. But by the 1960s — the period in which “Mad Men” is set — America was changing, and the whole idea of a family restaurant was becoming antithetical to the times, especially with the explosive growth of fast food restaurants.

In 1976 — the nation's bicentennial— author Max Apple published the superb collection “The Oranging of America and Other Stories,” whose title work fictionalized the original Howard Johnson. The story means to liken voracious 20th century American commercialism to the theme of manifest destiny in the 19th century. Howard Johnson sees it as his right to blanket the country with orange roofs, just as American pioneers saw it as their God-given obligation to push westward to the Pacific.

It is not much of a leap to say that the partners at Sterling Cooper share a self-justifying belief in their own right to market products with little regard to cost — not the cost of the products themselves, but the personal, emotional and moral costs of valuing business and financial success above all else. The agency may not have the Howard Johnson's account, but the partners fully believe in their own version of “oranging.”

What better place to explore the brittleness beneath the passion of Don and Megan's relationship than in a booth at America's anachronistic family restaurant?

On the surface, Don's impulsive marriage to Megan could be taken as some kind of romantic whirlwind. In truth, it felt desperate, if not dangerous, especially as Megan became increasingly determined to have her own identity and purpose beyond being Mrs. Don Draper. Don never took her seriously when she announced she wanted to pursue acting again — he assumed she meant as a kind of hobby when she wasn't staying at home and looking beautiful. Megan wasn't about to cave and that fueled marital discord throughout the fifth season, but memorably when Don and Megan were at the Howard Johnson's. When Megan became perhaps the only human being in the 1960s who hated the orange sherbet, her rejection of the dessert represented a rejection of Don at that moment, and, by extension, his values, the ad game and commercialism as well.

I don't get too worked up when others say the show has plateaued or dragged here and there this season. Although there are episodes of “Mad Men” just as there are episodes of “Law & Order,” the show has a much bigger sweep than anything else on TV. To get a lasting purchase on it, it's best to consider at least several episodes together, if not an entire season and perhaps even the entire series. “Mad Men” isn't a show about what people do as much as it is about who they are and who they aren't. Scott Fitzgerald declared that “action is character” — something the writers of “Mad Men” seem to believe as well. The characters in “Mad Men” are so beautifully complex and nuanced, you can very easily just watch the show without worrying about deeper meaning.